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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/57858] AVX2: ymm used for div, not for sqrt
Date: Wed, 10 Jul 2013 06:37:00 -0000	[thread overview]
Message-ID: <bug-57858-4-vyBP1fPIGq@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-57858-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57858

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Actually, it isn't vectorized at all, because PRE attempts to be smart, figures
out that for the first iteration of the loop it can avoid computing the sqrt
because the result will be one, and moves thus the sqrt call into the latch,
but we can't vectorize any loops that have non-empty latches.
So, either the vectorizer would need to undo this transformation, or PRE not do
it at all, or arrange for it to be done only after vectorizations.  Richard,
any thoughts on this?


  parent reply	other threads:[~2013-07-10  6:37 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-09  7:55 [Bug tree-optimization/57858] New: " vincenzo.innocente at cern dot ch
2013-07-09  9:44 ` [Bug tree-optimization/57858] " jakub at gcc dot gnu.org
2013-07-09 13:49 ` vincenzo.innocente at cern dot ch
2013-07-09 15:33 ` glisse at gcc dot gnu.org
2013-07-10  6:37 ` jakub at gcc dot gnu.org [this message]
2013-07-10  9:51 ` vincenzo.innocente at cern dot ch
2021-07-30  6:06 ` pinskia at gcc dot gnu.org
2021-07-30  9:16 ` rguenth at gcc dot gnu.org
2021-07-30 22:56 ` pinskia at gcc dot gnu.org
2021-09-11  6:37 ` pinskia at gcc dot gnu.org

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